Analysis of the Correlation Length Amplitude of Nitrobenzene and Dodecane Binary-Fluid Solution

David Emery Simpson

2012

The correlation length amplitude was determined through light scattering measurements for a mixture of nitrobenzene and dodecane. The objective was to determine the validity of the values presented by An et al. [1] and Utt et al. [2, 3]. The light scattering was done by taking measurements of the intensity of a laser beam as it passed through the sample at temperatures close to the critical temperature. The critical temperature was determined to drift upwards with time, indicating an extremely small contamination, most likely water. For the testing period the critical temperature was determined to have a value of 28.783±0.005 degrees C. The scattering intensity data near the critical temperature was used to calculate the turbidity as a function of the reduced temperature. After producing a graph of the turbidity as a function of temperature, a correlation length amplitude was calculated by fitting the data. The value for the correlation length amplitude was found to be 0.207±0.004nm, which does not agree with any previous results. This result does not resolve the discrepancy of the data sets or prove that two-scale-factor universality is still valid.